source: http://www.securityfocus.com/bid/695/info
Hybrid Network's cable modems are vulnerable to several different types of attack due to a lack of authentication for the remote administration/configuration system. The cable modems use a protocol called HSMP, which uses UDP as its transport layer protocol. This makes it trivial to spoof packets and possible for hackers to compromise cable-modem subscribers anonymously. The possible consequences of this problem being exploited are very serious and range from denial of service attacks to running arbitrary code on the modem.
https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/19538-1.tar.gz
https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/19538-2.tar.gz
https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/sploits/19538-3.tar.gz